TelephonyManager.CALL_STATE_RINGING calls twice wh

问题:

I use descendant - class of PhoneStateListener:

 class CallStateListener extends PhoneStateListener {
@Override
public void onCallStateChanged(int state, String incomingNumber) {
      switch (state) {
          case TelephonyManager.CALL_STATE_RINGING:
              if (incomingNumber!=null)
              {
                // code for incoming call handling
              }


          break;           

      }
      super.onCallStateChanged(state, incomingNumber);
  }

this is my BroadcastReceiver:

class ServiceReceiver extends BroadcastReceiver {
     CallStateListener phoneListener;
    @Override
    public void onReceive(final Context context, Intent intent) {

        if (phoneListener == null) {
            phoneListener = CallStateListener.getCallStateInstance(context);


            TelephonyManagerSingletone.getInstance().getTelephonyManager().listen(CallStateListener.getCallStateInstance(context),
                    android.telephony.PhoneStateListener.LISTEN_CALL_STATE);


        }   
}

manifest:

  <receiver android:name="com.library.ServiceReceiver" >
        <intent-filter>
            <action android:name="android.intent.action.PHONE_STATE" />
            <action android:name="android.intent.action.NEW_OUTGOING_CALL"/>
        </intent-filter>
    </receiver>

but when I use it like this, I receive duplicate call in my CallStateListener. How can I fix this?

回答1:

When I tried your code, it run 10 times instead of running just once! It is better to declare phoneListener as a static variable in this case. That way you can guarantee that listen method will not be called more than once. Check this out:

public class ServiceReceiver extends BroadcastReceiver {
    static CallStateListener phoneListener;

    @Override
    public void onReceive(final Context context, Intent intent) {

        if (phoneListener == null) {
            phoneListener = new CallStateListener();
            TelephonyManager tm = (TelephonyManager)context.getSystemService("phone");
            tm.listen(phoneListener, PhoneStateListener.LISTEN_CALL_STATE);
        }

    }

}

Also, I have changed the way you deal with TelephonyManager - I couldn't find that TelephonyManagerSingletone that you mentioned in your code.

I hope this helps somebody!

回答2:

Not sure if it's a bug or a feature, but since API19 that happens with broadcasts.

For those who will search for the solution - you can keep track of previous state. Do stuff only if it is different.